Technical issues


The following updates are the most recent updates released for the Hearts of Iron II series (as of September 30, 2009):

Note that Paradox has officially confirmed that HOI2 and HOI2:DD updates are the final updates for those games. The last one for Arma was not officially confirmed but given the time that has now passed, it can be taken as final.

Bugs and Bug Reporting

There are no further updates being made to any version of HoI2. Any found bugs will need to be corrected yourself using the modding tools if possible.

Configuring Routers for Multiplayer Games

The first suggestion is to check the Router configuration library , hosted at the Paradox forums. It covers all of Paradox's games, and is a repository for successful router configurations.

If you are unsuccessful there, ask your questions in this forum thread . Many experts that lurk about the forums subscribe to the threads above, so your questions will be seen.

Even with v1.2 the "moddir" feature is still broken for multiplayer play. Thus if you try and play a mod in multiplayer it will fail. The only work around is to modify the main game itself.

Screen Issues

Screen Flicker

If you are experiencing screen flicker at seemingly random intervals while playing the came, the following steps may be of use, as prescribed by Castellon:

  1. Rename the AVI folder to AVI_back
  2. Set the color depth to 16BIT
  3. If you're using the auto-hide feature of the task bar, disable it.
  4. If you have an Explorer window searching for a file or displaying search results, close it.
  5. Turn off everything in the background like E-mail/ICQ/Messenger, Virus protection and everything in the system tray beside the clock.
  6. Update your Windows, update your Video card drivers and audio card drivers. Then repeat steps 1-3.

98% of flicker problems are caused by other programs running in the background.

Also, alt+tabbing tends to increase screen flicker.

How to run Windows with minimal load of background services

Screen Resolution

According to developer Johan, the screen resolution for the game is locked at 1024x768. There is an unofficial patch that can alter the value, though. You can also take a look at screen related utilities . If you have difficulty playing HoI2 with the "offical" resolution, it might help you solve the problem.

Windowed Mode

If you want to play Hearts of Iron 2 in window, you must apply some unofficial "patch" first. Look at screen related utilities for concrete one. For Doomsday, there is new command line parameter WINDOWED, which activated windowed mode without need of any hacking. You must also set your screen color depth to 16bit (applies to both Hearts of Iron 2 and Doomsday) prior to running game in a window. If you don't do that, you'll get error message and game won't run.

Game Slow downs

The game gradually slows down as time progresses. This is especially true of a 1936 campaign, and generally starts around 1942 or later, depending on your CPU speed. Generally, this occurs due to the large number of units that have been created, and the amount of work the AI must perform every game hour to determine what should be done with units. Testing this issue has led to the conclusion that CPU speed has a significant effect on game speed.

The Doomsday scenario is a good test for these slowdowns due to the large number of units. Each test was conducted by choosing the nation of Tibet, setting game speed to maximum, and timing how long it takes for one month of game time to elapse. Testing produced the following results:

User Brand Type Speed Cache RAM Scenario time
Lennartos Intel Quad Core 3.7 Ghz 12MB 4 GB 1 min, 25 s.
SBR Intel Core 2 Duo 2.4 Ghz 8MB 2 GB 2 min, 26 s.
Bholstege Intel Core 2 3.0 Ghz 1 MB 4 GB 2 min, 30 s.
BBasgen AMD Athlon 64 2.2 Ghz 0.5 MB 2 GB 3 min, 28 s.
forlath Intel Pentium M 2.0 Ghz 0.5 MB 1 GB 3 min, 30 s.
The RC Intel Pentium 4 2.6 Ghz 0.5 MB 1.5 GB 5 min, 50 s.
MacLeod Intel Pentium 4 2.4 Ghz 0.5 MB 1 GB 8 min, 18 s.
forlath Intel Pentium 4 3.4 Ghz 0.5 MB 1 GB 9 min, 30 s.

Helpful Fixes


This change will allow you to both load and play the game much faster, but it only works if you use counters instead of sprite. Note that the file to be left alone in those folders do not have to be the one mentioned. Any of the other files will do as long as their file name match.

  1. Open HoI 2 directory\GFX\map\units.
  2. Backup this folder and its subfolder just in case you want to play with sprite again later or if anything wrong happens.
  3. Delete all files in HoI 2 directory\GFX\map\units except "T-BATTLESHIP A-WALK C-MIN L-1 D-NW.spr".
  4. Open HoI 2 directory\GFX\map\units\bmp.
  5. Delete all files in HoI 2 directory\GFX\map\units\bmp except "T-BATTLESHIP A-WALK C-MIN L-1 D-NW.bmp".
  6. Start the game and feel the speed.

Ghost Fleets

Ghost fleets began as a problem in the HOI2 DD expansion pack and continued until ARMA version 1.3, when the problem was finally fixed. The net result of a Ghost fleet can be tens of thousands of non-existent ships in a port. The sheer number of units involved creates enormous lag on the game engine: the main symptom being a delay at a certain hour of the day for seconds or even minutes.

Event History

Save games grow very large over time, depending on your event logging settings. In a default installation, the size of the game file will double in less than 10 years. Minor speed improvements can be made by deleting the event history.

Delete all units

While late game slow down is not really caused by a large number of units, deleting all units does help. Lord Finnish created this event: Kill all AI units


If you find the movies annoying, and prefer to open the game and go somewhere else while it loads (thus not being there to skip over the movies), there's a simple way to get rid of them. The only movies in the game are the ones at the start. Just rename (or delete) the avi directory where you installed HoI2 and the game will just skip over them.

General problem Solving

It is difficult to track problems effectively in current jungle of software products and their versions. When problem pups up, it is best to go from simple to more complex solutions. Here is recommended procedure for solving problems (it may work with problems related to other games/programs too):

  1. Refer to forum first. Your problem may have been addressed already. If you don't succeed there, try following procedure.
  2. If problem showed up recently and you were able to play before without problems (in same conditions), try to remember what has changed since then and focus on it.
  3. End all programs and tasks which are not really necessary. Use CTRL+ALT+DEL and 'Task Manager' to end tasks.
  4. In Windows 2000 or XP Professional you may also want to stop unnecessary 'Services' running on backgound. Type 'services.msc /s' in 'Run' (Start -> Run) to run console to view and manage services on your system. You require administrator's right to do so. It may help improve performace and limit possible problems. List of services you must have running may vary from system to system. Be careful when stopping services! ( How to run Windows with minimal load of background services )
  5. Installing other games with different (and sometimes problematic) version of DirectX may be cause of problems. In this case uninstalling DirectX ( DirectX Uninstaller ) first. Then download latest version of DirectX (if you don't have it already, here ) and install it.
  6. Reinstall game. If you want to preserve your data (savegames), archive them first (by copying/moving them to non game folder). Saves are stored in '\scenarios\save games' subfolder of directory where you installed HoI2. Then uninstall game by using uninstaller and delete remaining data manually (delete your HoI2 installation directory). Then install game with all patches and restore your archived savegames.
  7. If problem is still there, post in forum and pay attention to How to Report a Bug .
  8. In-game speed increasing trough message logging : Whenever possible disable evens from game log : for example another nation trade with third nation, another nation influenced/failed to influence third nation, another nation diplomatic deal with third nation, any logging of player aggreeing/refusing trade or diplomatic action suggested by AI is by default also written to game log. One has to be careful what is doing and if one needs any log evidence. It is always useful to go carefuly trough message settings in game menu and select what should be logged an how (4 levels of notification - none - log - window - pause game with window). Consider events that are not necessary for your gameplay and set them not to be displayed at all. Exclude all duplicate messages pointing to one occasion for example do not log demand territory but log give-in/refuse of demand territory.